Cells were subjected to cross-linking. After fixation with 1% formamide, cells were sonicated to shear DNA. DNA-protein complexes were incubated with Protein G beads (GE Healthcare) and anti-histone modification polyclonal antibodies (H3K4me1/H3K4me3/H3K27ac/H3K36me3). After washing the beads, immunoprecipitants were eluted with 30 µL of Tris buffer. Multiplexed ChIP-seq libraries were prepared from 10 ng of immunoprecipitated DNA fragments using NEBNext ChIP-seq Library Prep Master Mix (New England BioLabs). For sequencing using GAIIx (Illumina), cluster generation was performed using TruSeq SR Cluster Kit v2 (Illumina). Each lane of flow cells contained one sample. Sequencing was performed in single-read run mode with a total 76 cycles, including a 75-bp read and one cycle for phasing.